This invention relates to dynamoelectric machines in the form of electric motors, and more particularly, to a simple, effective way of controlling operation of a motor when used by different manufacturers for different purposes. While the invention is described in particular detail with respect to its application in appliances, those skilled in the art will recognize the wider applicability of the inventive principles described hereinafter.
As is well-known in the art, electric motors are designed so that a particular motor has a different set of operating characteristics for one application, and another set of operating characteristics for other applications. Heretofore, motors were designed and tested with respect to a specific application until the operating criteria met desired goals. For example, with heating and air conditioning systems (HVAC), it is common to employ a motor to drive the blower for the HVAC system. The motor design can vary depending upon a number of anticipated load characteristics. The load characteristics, in turn, are a function of a number of variables, including the type of air handler used with a motor, and can vary from one manufacturer to another. The problem is further complicated because of the variety of electric motor xe2x80x9ctypesxe2x80x9d available for use in HVAC applications. For example, induction motors long have been the predominant choice in blower applications. More recently, brushless permanent magnet, switched reluctance, controlled induction, and similar electronically operated motors have found use in such applications.
While a motor design for a blower application has a general set of operating features, each manufacturer incorporating a similar motor in its product wants or requires a different set of operating characteristics, because of that particular manufacturer""s construction or the manufacturer""s perception of his customer""s needs. Even a single manufacturer often provides a series of models having varying capabilities. As a consequence, motor manufacturers heretofore have provided a number of different models of essentially the same motor design altered to accomplish the specific needs either of a particular original equipment manufacturer""s (OEM) customer""s requirements or, to satisfy the needs of the various OEM manufacturers. The large number of motor models, in turn, creates a problem for the motor manufacturer. Parts inventory and overhead costs increase with increased part numbers. Even when such costs are minimized, however, the motor manufacturer""s assembly line often requires shut down in order to convert from one model to another model, thereby increasing labor costs.
The OEM manufacturer also incurs increased costs because the OEM must stock and track a variety of motors for its various product lines.
It thus is seen that a motor manufacturer can reduce costs if the manufacturer had the ability to produce one version of a motor for a particular application, the motor being readily adapted after manufacture, for each different OEM""s particular set of operating requirements. It also is advantageous to enable a particular motor to be used across a range of models for a particular OEM, based on function and performance of any particular model. Another advantage of our invention is that the OEM manufacturer is able to supply motors to fit new applications more quickly.
One of the objects of this invention is to provide a drive apparatus for a dynamoelectric machine.
Another object of this invention is to provide a drive apparatus for a dynamoelectric machine which enables essentially the same dynamoelectric machine construction to be used in a variety of versions of an appliance.
Another object of this invention is to provide a drive apparatus which is adaptable after manufacture to a variety of usages.
Another object of this invention is to provide a motor drive incorporating a microcontroller which has a set of parameters or an operating program sequence for the motor stored in it, a second memory having a series of data stored in association with it, and switches operatively connected to the microcontroller to enable the microcontroller to select the appropriate data for operation of the motor.
Another object of this invention is to provide a drive means with an associated motor capable of use over both a wide range of manufacturers and over a range of products of a single manufacturer.
Another object of this invention is to provide a drive which is designed to operate an electric motor satisfactorily under a wide range of selectable conditions.
Another object of this invention is to provide a drive apparatus which reduces inventory control problems for both the motor manufacturer and the original equipment manufacturer.
Another object of this invention is to provide a motor drive which is low in cost and which is readily associated with the motor structure.
Still another object of the invention is to provide a motor and motor drive in which operative characteristics of the motor can be changed without the use of special tools or equipment.
Other objects of this invention will be apparent to those skilled in the art in light of the following description and accompanying drawings.
In accordance with this invention, generally stated, a drive apparatus for use with an electric motor is provided having a low cost microcontroller adapted to operate a motor drive. The motor drive is operatively connected to the electric motor to control at least one of the current or voltage of the motor. The microcontroller supplies control information to the drive. In the preferred embodiment, the microcontroller includes a program module in the form of a ROM for controlling motor operation. A second and nonvolatile memory module in the form of an EEPROM is provided for storing motor operating characteristic information, the information being accessible by the microcontroller. Multi-position switches are connected to the processor module. The data in the second memory module determines the function of the switches. Data in the second memory module also determines the operating condition (values, parameters) of the drive apparatus. A separate programming device is used to download data to the microcontroller and to the second memory module. A plurality of switches, for example, are selectable by an installer of the motor, and the switch settings determine which functions the program module executes and how the program module uses the data stored in the second memory module. With this arrangement, one motor design may be used for one set of operating characteristics of the motor, while a second set of operating conditions may be obtained merely by changing the switch settings. In the alternative, data may later be loaded to the nonvolatile memory which alters the information selectable by the switches and the program flow thereby alters the operating characteristics of the motor.